1. Field of the Invention
The present invention relates in general to migrating subscribers between first and second cellular technologies, and in particular, to using an inter-machine trunk (IMT) to support service migration within a carrier's own systems with wireless local number portability (WLNP) functionality.
2. Description of the Related Art
In the past, a carrier did not own, or operate on, more than one cellular technology, for example, both time division multiple access (TDMA) technology and the global system for mobile communications (GSM) technology. So there was no need to traffic a message from a first technology to a second technology. Service migration is defined as the ability for the carrier to deprovision a subscriber from one technology and provision the subscriber on the second technology while allowing the subscriber to keep their same phone number. Currently, numerous carriers are moving their services from a first technology to a second more advanced cellular technology.
The FCC mandate of WLNP for wireless system has recently been enacted to support subscribers in changing carriers. That is, systems must be put in place that allow for local number portability such that a subscriber can take their mobile directory number (MDN) if they decide to move from one cellular/PCS carrier to a new cellular/PCS carrier.
However, the problem faced by carriers was determining how to support the migration of mobile directory numbers (MDN's) from one technology to a second technology, for example from TDMA to GSM, without requiring the subscriber to obtain a new MDN.
In the past, the solution was to use a form of sequential validation. Conventionally, validation was performed first for one technology, and if the validation yielded a false response, then the validation is redirected to the second technology. This solution provided a form of validation which required the additional use of machine trunks. In addition, this solution also did not take into consideration the use of WLNP functionality.